


The Best Time Steve and Bucky Were Cursed

by Molly_Ren



Category: Captain America (Movies)
Genre: Belly Kink, Belly Rubs, Eating Disorders, Feedism, Hurt/Comfort, Multi, Mutual Weight Gain, Stuffing, Weight Gain, feederism
Language: English
Status: In-Progress
Published: 2015-09-30
Updated: 2017-04-07
Packaged: 2018-04-24 02:42:46
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 6
Words: 7,601
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/4902493
Author URL: https://archiveofourown.org/users/Molly_Ren/pseuds/Molly_Ren
Summary: <blockquote class="userstuff">
              <p>Steve, Bucky, and Nat are just starting to figure out this "poly" thing. At the same time, Steve and Bucky's bodies begin changing in unexpected ways.</p><p>Also: consider this your trigger warning for disordered eating. No one has a real-world eating disorder in this story, but lots of binging and starvation happens.</p>
            </blockquote>





	1. A Bite or Two

**Summary for the Chapter:**

> Steve and Nat have lots of sex while missing Bucky. Steve also makes his favorite fetish dream come true by accident.

Natasha brushed her sweaty hair out of her face, then leaned over to kiss Steve’s plump belly before laying her cheek against it. “Nice to achieve your dreams, huh, Rogers?”

Steve had one arm flung over his eyes so she couldn't see his expression, but he sounded very happy and sleepy. ”Sex every day _is_ nice…”

“No, you goof. I mean _this_.” Natasha gripped his tummy, just hard enough for him to feel her nails.

“What?” said Steve.

He sounded shocked, so she decided to spell it out for him: “There’s a little bit more of you here now than there was last week.”

Almost before she realized he’d moved, Steve was out of bed and trying to look at himself in the half-length mirror over Natasha’s chest of drawers. She bit her lower lip to keep from laughing. “Wait… you didn’t _know_?” Steve had come into his own in the last few years, but he still had moments when he could be as over-excited as any golden retriever.

“I haven’t been _trying_ to gain--” said Steve, still twisting around to look at himself. Then he made a dismissive noise. “You’re just not used to seeing me when I’m not cut.”

“I’m pretty sure you didn’t used to pooch out around the belly button like that,” she insisted.

“But I haven’t been _doing_ anything,” Steve said. He ran both hands down his belly, half convinced that he was seeing what he wanted to see and not what was actually there. “Are you sure?”

Nat got out of bed, and knelt to mock-seriously examine his belly. “Well,” she said, “I couldn’t do _this_ before,” and nipped the soft flesh right below his navel.

It had been a long-running SHIELD pastime to speculate on whether Steve’s serum gave him as quick a recovery time for sex as it did for everything else. Today, Natasha was pleased to find out that all of the rumors were true.

* * *

 

“You seem calm about it,” Nat commented a week later. She’d noticed Steve was wearing a new pair of exercise pants to accommodate his belly, which was still growing despite his protests that he hadn’t changed his diet or his exercise regimen.

Steve didn’t look up from whatever game he was playing on his Stark phone, so she tried again: “Most people would freak out if they went up a size in two weeks.”

Steve looked up then, considering. Then he shrugged. “Just another weird body adventure.”

Nat smiled despite herself. “What does that mean?”

“After you shoot up to six foot one and gain more than a hundred pounds in just a few minutes, a little extra weight every now and then isn’t that alarming.” He thought he'd achieved just the right amount of casual bravado, but Nat didn’t reply, which he knew meant she didn’t agree. 

“Don’t worry, Nat,” said Steve finally. “If it gets worse I’ll go to Banner, I promise.” And then, so she’d feel better, he told a white lie: “I’ve probably just been eating too much ice cream lately.”

“Pining for Bucky?” she teased, and he knew she’d relaxed.

“Yeah,” said Steve, “a little bit.” This time it was the plain truth, and he looked so sad that Nat couldn’t help admitting to herself how much she missed Bucky too. It would be just her luck if something turned out to be horribly wrong with one of her boys only three months after they'd all decided to try to date.

In order to forget about this train of thought, she lightly pinched Steve's soft belly. "Guess you miss him so much it’s slowed down your metabolism.”

Steve smiled. “Maybe.”

"Well, fortunately for you he'll be back in a week." Nat rubbed the plumpest part of his belly, a new habit that Steve was quite getting to like. “Because if you keep going like this, we’re going to have to get you a new suit.”

Steve put his phone down for good, then gave her a long kiss. “You say that like it’s a bad thing.”

* * *

 

Nat was surprised to get a video call from Bucky a day before he was supposed to be back.

At first, she didn’t realize there was anything extraordinarily wrong. He looked hollow-cheeked and miserable, but that was often the end result of a mission. His webcam showed a nondescript hotel room and a table piled high with dirty dishes, but that was also often the end result of going to a city and being unable to go out for fear of being recognized.

She began to worry when Bucky didn’t seem to know what to say. They talked about Steve for a little bit--an inexhaustible topic--before Bucky finally said, “I’m so _hungry_ , Nat.” He said it in an odd way.

“What do you mean?” she asked.

Instead of answering, Bucky pulled his shirt up. Nat could see the hollow of his stomach, the curves of his ribs. He’d lost an alarming amount of weight in a little less than a month.

If she had been Bucky’s superior instead of his lover, she would have demanded “Sitrep!” Instead she said softly, “You okay?”

“I’ve been eating toilet paper.”

“What?”

“I was… waiting.” Nat knew that this was the short way of him saying he’d been on assassin’s watch, lying still for hours in a tiny apartment or attic with only a long-range rifle for company. “And I couldn’t leave. And I remembered something I’d read in an article, about how sometimes models will eat toilet paper even though it doesn’t help, because it makes them feel full. So I sat there eating paper and I was so hungry couldn’t stop.”

Nat kept her voice calm. “Do you have water?”

“Yes. I’ve been eating and drinking all kinds of things, Nat. It just doesn’t help.” She watched him press his knuckles into his belly, grimacing as he tried to massage away the hollow ache. He didn’t understand what his body was doing, and had called her because she wouldn’t panic like Steve would.

“Maybe it’s something to do with the cold?” Bucky _was_ in Russia, after all.

“It’s never been like this before. Not even when I was--” he swallowed, pushing back bad memories.

“Maybe it’s something to do with having an augmented body? You do burn more calories, on average…”

Bucky did not look comforted.

“You’ll be home tomorrow,” she said firmly. “Just hold on til then.”


	2. Hunger

**Summary for the Chapter:**

> Bucky gets off and Steve gets a clue.

When Bucky got out of customs, Steve’s first expression upon seeing him was one of shock, quickly smoothed away. _I must really look like shit_ , Bucky thought as Steve hugged him hard, but that was as far as he got as he looked up and down his boyfriend’s new body.

When he'd left Steve a little less than a month ago, Steve's waist had been famously small. Now his belly bowed out, his arms were thicker, and there was even a little bit of softness under his chin. “Wow,” said Bucky, “you got…” and then bit off the rest of what he was going to say. His cheeks went pink.

“'Fat'?” said Steve, slinging an arm around him.

“'Beefy'?” Bucky suggested, his voice going up a little bit. He was quite shocked at Cap’s new appearance, but found he liked it more the more he looked at Steve.

“Nah, I like 'fat' better,” Steve said, winking.

“I’m glad,” said Bucky, then took a deep breath to give Steve the bad news. “You know,” he said, “my metabolism’s doing weird things too--”

“Yeah, he really chubbed up while you were away.” Natasha seemed to materialize by Bucky’s elbow, looking deadpan and wearing the blandest winter coat and knit hat he’d ever seen.

He felt his heart do a funny flip when he saw her, the same way it always did even after nearly four months of dating. “Hey, doll.”

She smiled and put his arm in his. Just like that, he felt like the luckiest person alive. He was between the two people he loved best, and even the stomachache he’d had for three long weeks was starting to ease. Maybe he didn’t have a terrible wasting disease after all!

“So we figured we’d let you pick,” Steve was saying as they walked towards the parking lot. “Do you want to go out to dinner? Or if you’re too tired--”

“God, I just want to go _home_ ,” said Bucky. He put his arm around his boyfriend’s new, softer waist and squeezed. “Can we go back to the apartment and order Thai food? I’ll be interesting tomorrow, I promise.”

Nat kissed him. “I got _The Fast and the Furious_  on DVD.”

“I _love_ you,” said Bucky, looking so grateful that Steve laughed.

* * *

 

A week later, Bucky was lazing on the sofa with his belly out. It was round and plump, and he palmed it with one hand while lazily stroking himself through his boxers.

Bucky had never fully explained his brush with starvation to Steve. The first night home he’d spent snuggled between Nat and Steve on the couch, he’d discovered halfway through his first bowl of curry that his endless hunger was finally abating. He couldn’t believe it at first, then had silently given a prayer of thanks to whatever deity was responsible before stuffing himself to bursting with red curry, beer, and Nat’s freshly baked chocolate chip cookies. Afterwards, he’d fallen asleep with his head in Steve’s lap, Nat obligingly rubbing his belly as both of them looked on with great amusement.

Nat had been regularly checking in with him ever since, of course. Mostly by text, since he and Steve had been joined at the hip ever since Bucky's return. Though he had come back noticeably skinnier, he'd passed the post-mission physical and both he and Nat had finally begun to accept that there was nothing seriously wrong with him. To distract himself from any lingering doubts, he'd thrown himself into the requisite two weeks of R and R following his mission with hedonistic abandon, going on runs with Steve every morning and then collapsing in the apartment to binge-watch old movies and new TV with all the snacks and beer they could ever want. Every day they did something new--museums, art shows, farmer's markets--and every night he would have sex with his new, chubbier boyfriend and sometimes his girlfriend (poor Nat was stuck playing politics on the Hill instead of getting a break like she deserved). The obvious pleasure Bucky took in memorizing Steve's new curves had finally led Steve to open up about his desires, and they'd spent a weird but amazing evening perusing YouTube for belly videos and wondering what Steve would look like if he gained even more.

His appetite was still completely ridiculous, though, even for a super soldier that required twice as many calories than a normal human just to function. Over the next few days, Bucky had eaten his way through most of the apartment’s cupboards, destroyed a New York style pizza and devoured more Thai food than he’d ever had in one sitting. (This was how, incidentally, he'd discovered that Nat gave the best belly rubs on earth.) Now, a week after coming home, his boxers were tight in the waistband and his shirts pulled tight over the curve of his belly, but he was too blissed out to care. The memory of agonizing hunger was still too fresh.

Speaking of tight… Bucky shifted on the sofa, rubbing his swollen stomach. He fancied it pushed up a little further than it had a few moments before, which wasn’t too surprising. He gorged himself so thoroughly over the past couple hours that it would be amazing if he _wasn’t_ bloated (nearly three orders of Chinese will do that to you), and his belly was only going to get puffier over the next hour as his enormous feast digested.

What had he been thinking about again? Oh yes, his weird starvation scare.  Had it been "just another weird body adventure", as Nat had quoted to him? Had the stress of his mission, combined with the new frustration of being separated from his partners right after they'd decided to form a triad, made his metabolism overreact? Had some essential thing in his diet gone missing, triggering an attack of [pica](https://en.wikipedia.org/wiki/Pica_\(disorder\))? They'd probably never know.

In the meantime, Steve was out seeing an art-house movie, and Bucky planned to take full advantage of his solitude to give himself a couple long, slow orgasms. He cupped the fullness of his belly below his navel, giving it a gentle squeeze, and shivered at how deliciously plump it was. He felt a big gurgle start in his lower belly, then gave an equally huge belch. That should have been a relief, but afterwards his belly only felt tighter and rounder than before. How could that be?  

Bucky spent the next few minutes teasing himself, massaging his swollen stomach in ways that echoed the way Natasha would when they were in bed together. He lightly squeezed his round sides to make his tummy bulge out even further in front, then fingered his navel, then lightly jiggled it in order to coax out more belches add ease the growing pressure. By then he was warm enough that his cock was poking out of the waistband of his boxers, and he freed himself. He lightly stroked his cock back, so that it touched the curve of his tummy, and groaned.

God, he felt heavier now than when he’d finished eating: sprawled out on the couch in an effort to make as much room as possible for his belly to bloat. With another, louder groan and another big belch he pushed himself to go look in the bedroom mirror, holding his swollen belly with both hands.

He didn’t make it past the bed, though. Instead he stripped off his t-shirt and, with and effort, managed to push down his boxers the rest of the way before getting on all fours on the bed. He thrust his cock against the pillows, desperate for a little friction, and it was only with a supreme effort that he stopped himself before turning to look at his new body in the mirrored doors that led to their closet.

Bucky couldn’t believe how low his belly hung. It looked half again as big as it had when he had finished eating, and it was so quiet in the apartment now that he could hear it rumbling with digestion. He gave a small burp, then another and another as he alternately stroked his cock and his enormous belly, before dipping even lower to grind against the pillows.

* * *

“Bucky?” Steve’s voice from the living room made him freeze up, even though this was hardly the first time either of them had seen each other naked. He'd been so absorbed in pleasuring himself that he hadn't even heard the door open-- some assassin he made!

Steve was putting his keys down now (Bucky could hear the jingle.) He had to swallow a few times before he could speak, hoping that Steve would be just as excited by his gluttony as he was. “In the bedroom!”

Steve knew what _that_ meant. He came in with a huge grin on his face... which turned into amazement and awe as he took in Bucky laid out in all his glory on the bed, ass in the air and belly grinding against the pillows. Weirdly enough, he was also holding a huge bag of candy, but Bucky lost track of it in the rush to get Steve’s clothes off as quickly as possible. 

Bucky needn't have worried that Steve wouldn't find him attractive in his glutted state. Steve used his strength to flip Bucky over onto his back, then attacked the new curve of his belly with his mouth while pumping his cock. Bucky was still so keyed up from before that he maybe lasted three minutes before the warmth of Steve's lips below his navel got to be too much for him and he came hard, splattering his belly and (unintentionally) Steve's face.

Bucky was so satisfied and drained afterwards that he took a little nap--no more than a few minutes or so--before waking up to see Steve was standing by the bed. He was weighing the fallen bag of candy in his hand--it looked to be half-empty--while staring at Bucky’s belly with a look of consideration.

“Buck?” he said slowly. “What did you say happened to you in Russia again?”


	3. Science Bros

**Summary for the Chapter:**

> Bruce tries to figure out what's causing Bucky and Steve's bodies to change, and finds worrying parallels to his own out-of-control transformations.

“Working late?” Tony asked. He kissed the top of Bruce’s head, receiving only a brief grunt of acknowledgement in return.

He didn’t have to ask what Bruce found so engrossing. The 3D display in front of them was crowded with models of Rogers’ and Barnes’ bodies at their current weight and those of a year ago, along with oodles of graphs that Bruce had made to try and force their metabolic readings into some kind of pattern. Carelessly opened videos were scattered all over the digital workspace, most of them playing on loop.

“I just don’t understand it…” Bruce sounded completely exasperated, and Tony raised an eyebrow. It was very seldom that a problem in biology eluded the Big Guy.

“What’d you find?” Tony asked. Semi-consciously, he found a cookie among the half-empty snack bags scattered over Bruce’s desk. He was ready to settle in for what might possibly be a long session of brain-work.

“It’s what I _didn’t_ find.” Bruce punched a button and brought up a video of Barnes in a laboratory setting. He’s shirtless, festooned with wires, and sitting on what Tony recognizes as a gurney in Bruce’s lab.

Despite the sterile background, Tony feels a little stab of lust at the sight of Bucky’s body. The former Winter Soldier looks deliciously well-fed, with a round belly and little love-handles spilling over the waistband of his flannel pants. Barnes is also relaxed in a way Tony’s never seen before, smiling to someone off-camera before he lifts a marked gallon jug to his lips and starts chugging--

“Whoa, whoa!” Tony exclaimed. “That’s a _test_?!”

“It’s for capacity,” Banner starts in his best lecturer’s manner, before registering that the expression on Tony’s face was more of glee than shock.”I should have known better than to show _you_ this one,” he said, glaring.

“Hey, I’m just looking!” Tony protested, but Banner had already switched to a theoretically more neutral vid of Bucky jogging on a treadmill. Despite his bigger belly, he was going along at a good clip.

“ _Anyway_ ,” said Bruce, bringing Tony firmly back to earth from watching his coworker’s boyfriend’s belly jiggle. “Even for someone with an… augmented metabolism...Barnes’ recovered from an unexpected weight loss within _two days_ of returning from his last mission. He’s since gone on to gain thirty pounds with no ill effects. That contradicts the trend of every single measurement we took of him _or_ Rogers over the past _three years_. So either every single tool we have in the lab has been tampered with, or…”

“Or?” Tony had finished off the last few cookies.

“Or I don’t know!” Banner took a deep breath to re-channel his annoyance. “Bloodwork checks out, brain waves are normal… even his genes are the same.”

“Weird,” commented Tony.

Banner agreed that it was indeed weird. He looked morose for a moment, then took off his glasses and scrubbed his hands through his salt-and-pepper hair. Tony suddenly realized that Bruce was profoundly exhausted, and kicked himself for not noticing sooner.

“Hey,” he said in a soft voice, touching Banner’s shoulder. “C’mon, you’ve worked a full day already…”

Banner swung back and forth in his padded office chair--one that Tony had specially ordered to accommodate his friend’s growing bulk--in a way that Tony had come to recognize as petulant. There was definitely something else going on here besides the late hour and frustration at being unable to solve a problem.

Above them, the videos continued to autoplay: various snippets of Steve and Bucky doing strength exercises and being weighed and measured. There was no sound, but in one it was clear that Rogers had come in at the wrong time during Bucky’s testing and distracted him. A strained-looking Bruce was silently berating them both.

“They are the _worst_ test subjects,” said Bruce as he gazed up at the video. “Both of them lied, and thought I wouldn’t _fucking_ notice...”

Tony thought of doing something more demonstrative than having his hand resting on Bruce’s shoulder, then thought better of it at hearing Bruce swear. “What did they lie about?”

“They both asked me,” said Bruce, “if they would gain more weight, pretending that they were concerned about it. But as far as I can tell, they’ve been doing it _on purpose_! Just playing with gluttony like it was a carnival toy. I asked them not to  make any major changes for _one week_ , just so I could get a base reading, and they both showed up ten pounds heavier than they did last week--!”

Tony’s libido had a thousand questions about how Steve and Bucky could play with their weights like yo-yos, but he wisely stayed quiet. Banner was clearly feeling a thorn somewhere, and Tony was willing to wait until Bruce found it so that he could help him pull it out. Together, they’d managed to cure far deeper wounds in Bruce’s psyche than this.

Banner wound down his rant, then gripped his soft belly. “I wouldn’t wish _this_ ,” he said, “on anyone.”

And there it was. Over too-few months, as Banner had become happier and settled in the Tower with someone who loved both him and his big green ragemonster, he’d nearly doubled his weight. _Everyone_ had noticed. Hawkeye had been a dick about it. Natasha had almost stopped talking to him. Colleagues had whispered about it. And Tony had… well, maybe not _helped_ exactly… Facilitated?

Tony cleared his throat, trying not to look at all the empty cookie bags (in a flavor which he ordered specially for Bruce) and thought aloud. “You think they’re… like you?”

The old quote about happiness making one expand aside, Bruce had begun gaining in a superhuman way mostly due to [the Hulk’s unforeseen machinations](http://archiveofourown.org/works/3804082/chapters/8474512). That two other super-people--especially those whose powers the Hulk’s serum was meant to mimic--were undergoing similar changes was potentially terrifying. Tony found himself becoming a little nervous despite himself. “Could they… each… have a Hulk inside them?”

“I hope not,” said Banner. “I really, really hope not.”

In the video above them, Banner had finished berating Bucky and was monitoring some lab equipment. Behind him, Steve and Bucky were having a fast make-out session that Banner was obviously far too aware of. Even from behind, Tony thought he looked like he wanted to die of discomfort from being so close to the overwhelming lust that radiated from both of them.

But there was also something wistful there, Tony realized as he watched Banner watch the video of the happy couple. Tony, despite his vanity, knew that Banner still felt the loss of his first partner keenly even though he was now partnered with a gorgeous playboy philanthropist. By contrast, Steve Rogers--”America’s sweetheart”, they called him--had had his first love miraculously given back to him. Both Steve and Barnes were… well, “glowing” was a good adjective, and it was enough to incite envy in even the most happily married heart. Hadn’t Pepper said something about them and Natasha…?

Tony’s line of speculation was derailed by the realization that Steve was wearing not just a snapback in the video, but _sweatpants_. And then, he miraculously knew just what to say to bring Bruce out of his funk.

“God,” said Tony with just the right amount of intellectual disdain in his voice, ”they look like frat brothers.”

Bruce chuckled. Suddenly the video wasn’t of the world’s most beautiful couple making out, but of two humpy college guys that hadn’t enough fashion sense between them to change out of their too-tight pajama pants (Barnes’ had cats on them). Sometimes, Tony thought happily, the jocks vs. nerds stereotype came in handy.

“Did you know,” said Bruce in a much happier voice, “that Barnes actually has a shirt that says “SUN’S OUT GUNS OUT”? It has those ridiculously enormous arm holes.”

“I did not.” Tony began massaging Bruce’s tight shoulders, and Bruce learned back to enjoy it.

“I didn’t think it was a real shirt.” Tony snorted. “And Steve’s busting out of his clothes--I don’t think he owns a single article of clothing that isn’t too small now. His shirt was so tight I could see his navel!”

“Scandalous,” said Tony, still grinning. His hands moved from Bruce’s shoulders to his love handles. And despite all his insecurity and jealously, Bruce couldn’t help but give in when Tony nuzzled his neck.

“Let them be happy, Bruce,” Tony murmured in his ear. Bruce made a wordless noise as Tony’s hands worked their way back up his body, lingering over the curve of his gut and squeezing one soft pec before pinching a nipple through his shirt. “After all, fat can be fun.”

Several long moments were taken up with making out, before Bruce forced Tony to come up for air. “Maybe it’s... not the serum,” he said in a dazed voice.

“Could be something in the water,” Tony suggested without thinking--he’d much rather use his lips to nibble Bruce’s ear.

“Mmm, yes…” Bruce mused. “Someone with access to all the private rooms in the Tower… someone with a very perverted, yet scientific mind…and possibly a strange sense of humor.”

Tony was so distracted it took him three whole seconds to realize that Bruce was looking at _him_ , pointedly. He put his hands up in protest. “Wasn’t me!”

**Notes for the Chapter:**

> Happy Thanksgiving to everyone from Fat!Avengers chat who have eagerly been awaiting this chapter. Christmas came early this year. :D
> 
> Fans of the cassiopea's Bruce/Tony fic might recognize this version of Banner. I liked reading her "Twice the Man" series so much I couldn't help trying to create a cameo for a "big guy" Bruce in my own story. Hope you like it, cassiopea!
> 
> Finally, if you want to see more stories I've written about stuffed queer boys, check out my original fic at [my Etsy store](https://www.etsy.com/shop/MollyRen)!


	4. Black Widow Moves In

**Summary for the Chapter:**

> Nat isn't going to let anything mess with *her* boys.

_Two weeks later..._

“I think we pissed him off,” said Steve as they left Banner’s lab. _Again_ , he added mentally.

Steve glanced at Bucky to see if he shared his flicker of remorse and received a shameless grin in return. “I thought he _loved_ Nat’s charts.”

“He didn’t love your pajama pants,” Steve retorted.

“I keep telling ya, Rogers: if I have to have wires stuck to me every week, I’m sure as hell not wearing a suit for it.”

Bucky’s pajamas _did_ have grinning cats on them, but Steve didn’t think it was because of their pattern that Banner had narrowed his eyes before giving a resigned sigh. The pants were the same ones Bucky had worn to his first appointment… only now they were skin tight over his meaty thighs and the waistband dipped under his thick midsection. They had made a bet with each other that they could each gain ten more pounds in a week, and the idea had proved to be far too exciting for them to heed any of Banner's warnings about messing with stuff they didn't understand.

Not like Steve was setting a good example, as he had been reminded when he disrobed in Banner’s lab only to find his jeans had left an angry red mark all around his belly. Thanks to both their serum-enhanced appetites (and Nat paying so much more attention to both their bellies… and the fact that they found each other eating to be incredibly hot...and maybe just a little leftover starvation fear) they were constantly managing to put away whole pizzas and gallons of ice cream and party-sized bags of chips between them, making gaining ten or twelve or even fifteen pounds in one week criminally easy. Steve, who felt like every single pound had gone to his belly, was only now realizing that he needed to buy new shirts.

Speaking of... Steve glanced over at Bucky, who still had that smooth assassin's walk despite wearing PJs, and suddenly realized that Bucky probably didn't have any other pairs of pants that fit over his wide thighs and growing ass. Just like that, Steve found himself half-hard and wondering what the next fifteen pounds would feel like, wondered how Nat would feel about having just a little bit more to grab--

 _I’ll be serious later_ , Steve promised himself.

* * *

 

It had taken a long while for them to “crack the code”, so to speak, on their seemingly conjoined appetites. The first clue had come that day when Steve had gone out to a movie and found himself unable to get full no matter how much popcorn and candy he ate, only to come home to an overstuffed boyfriend gone silly from the sugar rush. Another time, they'd been in different boroughs and Bucky had developed the bottomless appetite while Steve found himself seemingly growing plumper by the hour, just like when Bucky was in Russia.

Fortunately, this time they could communicate via text message and get together again before things went too far. Both Steve and Nat had received the same text message (“ _its happening again_ ”) and dead heated each other to Steve’s apartment, finding Bucky shivering on the floor and the kitchen trash piled high with useless takeout wrappers. Fortunately, soon after that whatever was affecting them released its hold: Steve had stopped feeling like he was about to bust out of his clothes, and Bucky’s stomach had stopped trying to gnaw on his spine.

Nevertheless, it had taken them almost two hours to talk Bucky down and get him to eat some toast to prove that his hunger could be sated and that he wasn't going to starve to death again. Natasha had stayed the night with them (thank god for California king beds), and Steve had woken up the next morning to find Nat had gone out, bought a whiteboard and markers, and was setting it up in the kitchen with headings like “food eaten”, “time” and “effect”. Bucky being upset had made her angry, and she was going to get to the bottom of whatever was affecting “her boys” even if they had to clock everything Bucky ate and every time they left the apartment to figure out the pattern.

Steve was impressed and a little intimidated. “This might take a while,” he said, looking at the data she’d already inscribed.

“Well, after that China mission I have some vacation coming,” she said, tapping her lower lip with a dry erase marker cap.

“What about Fury?” asked Steve.

She’d given him a smile that didn’t reach her eyes. “Fury will understand.”

And, just like that, the Black Widow moved in with them. Bucky knew it was temporary and because she wanted to help him through his starvation-induced terrors, but as he told Steve later, “I thought I’d have to wait five, ten years for something like this… I should have had a medical emergency sooner.” Steve punched him in the arm. 

* * *

 

Having Widow in their apartment was both strange and good, Steve reflected. Good in that simply having her there made both of them feel calmer about their bodies and more settled in their relationship. Weird in that the way she acted every day was a lot like how Bucky acted right after Steve had gotten him back from Hydra: bringing only a tiny go-bag, taking different routes to and from the apartment every day, and occasionally waking Steve up by slipping into his bed in the middle of the night like a cat.

But weird habits or no, she was _incredibly_ thorough. It was only a month or so after she'd moved in that she had a working theory about what was setting them both off, and Banner had to grudgingly admit she might be right.

The key was, in fact, proximity. Whenever one or the other of them left the apartment and went further than, say, a few blocks, something would shift all the hunger into Steve and all the fullness into Bucky (or vice versa). Fortunately, being in the same room again was enough to force a "reset", and the two of them would then go back to being able to eat and metabolize normally. Which sounded simple in hindsight, Steve reflected, but they had had to rule out a hell of a lot of environmental factors (activity, food intake, environment) before they got there.

It was Bucky that had realized that, every five resets or so, the two of them would find themselves with enhanced appetites _and_ growing bellies, as if being near each other doubled the impact of every bite they put in their mouths. And once they figured that out, it was only a matter of time before Bucky started to trigger it on purpose.

In different circumstances, Steve figured he’d be more than a little annoyed that someone else had any say in one of his most essential bodily functions. Bucky could very easily rack up two "resets" in a day by doing something as simple as going to the gym, coming back to kiss Steve as he lingered over the morning paper, and then going out to a movie and returning. Steve taking Nat out to dinner would be a third reset, because he could hardly be expected to stay in their apartment all day. Which meant that, without hardly any deviations to their usual routine, Bucky could help trigger a surge of gluttony _every two days_.

Steve still felt a little dazed when he looked back on all the food they’d eaten the first week after they'd cracked the code. Maybe it was something about growing up in the Depression, but figuring out how to trigger a surge made all three of them gloriously reckless. For a whole week, Bucky said, being hungry _and_ being full is going to be something that happens to other people... and Steve, instead of saying something cautious, had eaten an entire bushel of apples that first day. That night, his stomach was so full that it was swollen drum-tight, but all he wanted was _more_.

Nat, apparently, had no complaints about having both her partners suddenly sporting big, growing bellies. In fact, she seemed to encourage it, if the way she brought them food every day was anything to go by. Steve found out how delicious Russian pastries were, consumed what felt like his body weight in pizza and Thai and every other form of takeout, and watched Nat tenderly hand-feed Bucky every form of modern candy they could get their hands on.

More than anything, that week was a chance for them to spoil Bucky. Wordlessly, both Steve and Nat agreed that Bucky looked much better with a wide, soft tummy and a rounded face, all marks of his prior brush with starvation obliterated. Nat even went to sleep at night snuggled between them, Steve's paunch snugged into the hollow of her back and with her hand on Bucky's belly. Once or twice, Steve came back to the apartment after a candy run and found her using Bucky’s new, plush tummy as a pillow, though he was sure she would never admit to doing so in public--

* * *

 

"I'm hungry," said Bucky, breaking into Steve's reminiscences.

"Didn't you just drink a gallon of saline?" said Steve. He sneaked a glance at Bucky's belly, which quivered with every step he took.

"Yeah, but that was just water." Bucky slapped his water-round belly and burped. "Water just makes you hungrier."

"Is that how it works?" asked Steve rhetorically. He rubbed his rounded belly, feeling how soft he was now under the tight fabric, and shivered. He wanted to be tight again everywhere, though. A box of pop tarts each should do it...

Suddenly his belly growled, loud and embarrassing.

Bucky smirked at him. "See?" he said, tapping Steve's paunch. "He agrees with me."

 

**Notes for the Chapter:**

> If you remember this chapter having a different ending/title, that's because it did! I edited it because I wanted more stuffing put in, and also more Black Widow.


	5. Fat Boyfriends

**Summary for the Chapter:**

> Steve and Bucky discuss Bruce's findings while eating lots of Pop Tarts.

“What is the deal with those two?” asked Bucky suddenly.

They were back in Steve's apartment. "Who?" asked Steve, distractedly wondering if there was a better way to cook Pop Tarts than just two-at-a-time in the toaster oven. 

"Banner and Stark."

“Oh. I think... they’re like us,” said Steve. He meant "inverts," though now every time he used the word he could hear Nat's voice in his head: "It's just 'gay' now, Steve!"

“What, gainers?” said Bucky.

Fortunately the toaster popped, and Steve had the excuse of reloading it to give him time to consider the idea. “You know what? I think so.”

“Really?”

“Yeah, you remember--oh, wait, this was before you came here.” Bucky gave Steve a look of slightly annoyed fondness as he snatched a Pop Tart from him, as Steve was constantly forgetting how little Bucky actually had been around. “Well, Banner used to look very different, is all. He only came to live here with Stark after the Battle of New York--before that he was in hiding in India or something. Then in the last year or two he just kind of…”

Bucky smacked his own tummy as Steve looked for a suitable adjective. “Blimped up?”

Steve grinned. “Yes, but for the love of god don’t say that to his face! He might turn green.”

“I can handle him,” said Bucky, as if the Hulk were no more than a Brooklyn bully who wasn’t going to get away with putting a finger on his skinny boyfriend.

Steve snorted before he could stop himself. Bucky _had_ to have seen Banner transformed--hadn't he?--and the Big Guy was big enough to make even Captain America pause.

Bucky smacked his tummy again, managing to look extremely arrogant for someone who was not only extremely bloated but clutching a half-eaten Pop Tart. "You don't think I can? He may have a hundred pounds on me, but I bet I'm faster."

"Sure you can," said Steve, kissing him... and felt the soft expanse of Bucky's swollen belly pressing up against him. Which is how, with one thing and another, they found themselves ordering Chinese food at 2pm.

* * *

“It _would_ happen to you first,” said Bucky, disgusted. He was still struggling with his second order, and his stomach had grown so big that he couldn’t hunch over his food to inhale it properly.

"I'm not making you eat that," said Steve, even though just a few moments ago he'd been lying back in his chair, panting weakly as he cradled his rock-hard belly. Then their new magic power had kicked in: there was a faint flickering of muscles along his sides… he was able to sit up… his t-shirt pulled just a stitch or two tighter… and, finally, he rumbled out a big belch. In five minutes, he'd gone from burstingly full to slightly fatter and ready to go again... though for now, he was having fun sipping a beer and watching his partner struggle.

They were unsure exactly what was going on the first time it had happened. They had only nailed down the process after a day or two of trying every kind of ice cream Nat could find. ("Just don't explain to Banner exactly how we found this out, all right?" she'd said as she fed Steve a spoonful.) But as far as they could tell, the secondary effect of the weird conjoining they were now in was a spectacular increase in digestion. No matter what they were eating, once they got to a certain level of stuffed, Something would kick in. In moments, their bellyful would be mostly digested, and there would be a new layer of fat pushing their navels against their t-shirts.

As no one yet had a good theory as to why any of this was happening, no one knew whether or not this was an intended side-effect, a fun glitch, or the original superserum kicking into overdrive in response to their enhanced appetites. But in practice, it meant that, with enough food and determination, Bucky and Steve could clean out a buffet between them and waddle away with new big bellies hanging out of their clothes.

Oddly, though, the chub they gained through their new appetites seemed to work differently from regular fat. They seemed to burn it off quicker… though as Steve said, that might just be a side effect of having the ridiculously active lives and metabolisms of super soldiers. After a good workout, their fat tummies would be noticeably flatter (which Steve was privately relieved about, as he was still occasionally called on to do press conferences). After a two-day fight with some aliens, Bucky’s new paunch was gone altogether (though they wasted no time putting it back). Though that was hardly an issue _now_ , Steve thought to himself as he watched Bucky's belly straining against his t-shirt...

Bucky sat back, wincing, to rub his bowed-out sides. “Ugh. I thought drinking that much saline would give me an edge, but instead I’m so waterlogged I can barely get the food in.” He patted the upper arch of his belly, which was too swollen now to quiver, and jerked out a painful hiccup.

"Giving up?" asked Steve, amused. 

Bucky hiccuped again, which made Steve's cock respond in interesting ways. "Never."

Steve became so absorbed in watching Bucky that he actually forgot to eat himself, which just left more for Bucky. Every few minutes he would give big, watery belches, massaging the underside of his gut and wincing. Sometimes he would hiccup and that in turn would make him burp, which Steve found the most amusing of all. 

Bucky's belly was starting to make angry groaning noises, and Steve was actually wondering if Bucky had come to the limit of their new superpowers, when his bloated belly suddenly twitched, then relaxed and spread out as the change was finally triggered and all that food was transformed into fat. Bucky gave his rudest, most massive burp yet, smacking his belly with relief as it was suddenly soft and jiggly instead of tight and hard. In moments, his shirt was riding up over a marshmallow-soft belly, and his love handles were spilling over the waistband of his PJ pants. Steve was so in awe of this transformation that he choked on his beer.

Bucky definitely wanted to keep going after that. With Steve's help, he ate until his belly had expanded three more times, getting rounder and wider and softer each time, until his shirt stopped halfway down his navel and there was no hope of him fitting in his PJ pants again. Or getting them off-- they ripped as Steve helped him.

Then one thing led to another, and that was how Nat came home to find the kitchen strewn not only with half-eaten pop tarts, Chinese food cartons, and cellophane wrappers but a pair of Steve's boxers, which she left hanging from the ceiling fan in retaliation.

* * *

 

“You know,” said Bucky the next day, hefting his still-expanded belly after a heavy breakfast, “I like this. It’s a good size.”

“It’ll go back down after one training session,” said Steve, trying not to betray how much he agreed.

Bucky grinned and grabbed another bag of ranch Doritos. "Better make sure that doesn’t happen, then."

 

 


	8. Cookie Dough

**Summary for the Chapter:**

> Bucky likes extremes.

Shortly after Bucky's decision to "maintain" his new belly, Steve realized with great amusement that Bucky was outdoing himself whenever Nat stayed over. Which was quite a feat, considering his already-monstrous appetite. But Steve knew that Bucky, in addition to being a bottomless pit, was also a romantic at heart: he would eat six pizzas in a sitting if it would make his girlfriend happy (or horny). 

This also pleased Steve because he finally, _finally_ had some ammunition to tease Bucky with. Perhaps not as embarrassing as the times Bucky would tell Tony stories about Steve's efforts punch people out when he was still a 90-pound weakling, but good stuff nonetheless. _Especially_ when he'd come home to find Bucky exhausted and as overstuffed as a Christmas turkey, groaning if he was so much as poked. For Steve, it was a double win: not only could he give the Winter Solider shit for being laid low by something as innocuous as cookie dough ice cream, a few hours later Bucky's belly would be soft and sloshy and excellent to grab.

Bucky had the last laugh, though. Over the next six weeks, he went from merely big-belled to enormously, luxuriously, sinfully fat... and it slowly started to drive Steve nuts. 

It wasn't enough that Bucky was eating big just to maintain his new paunch, oh no. It's that he _pushed_ it, eating a little more each day to further expand his already superhuman capacity. Soon Bucky was out and out gorging every day, and Steve would come back from a meeting with Fury to find he was missing not only his boyfriend sleeping in the nude, but the sight of his nosily digesting belly growing even bigger. Once, he had come back to find Bucky sound asleep beside an empty two-gallon container of ice cream, and the massive belch Bucky gave when Steve woke him up, paired with the way his drum-tight belly looked under the sheet, make it impossible for Steve to concentrate on anything for the next week.

Even worse, Bucky had so little to do, being taken off duty until Banner could figure out just what was going on, he could spend hours every day doing little more than stuffing his gut and falling asleep. "You're lucky you're not a _real_ Avenger," the Black Widow would say to Bucky as she sat on his lap and hefted his overflowing gut. She looked very, very appreciative. Steve, meanwhile, was discreetly cutting back, as he had to be a parade marshal in a month and a half, and couldn't quite admit to himself that he was jealous.

 

 

**Notes for the Chapter:**

> If you like this story, check out [my original Kindle fic!](https://www.amazon.com/s?ie=UTF8&page=1&rh=n%3A133140011%2Cp_27%3AMolly%20Ren)


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